This invention relates generally to electronic timepieces, particularly quartz analog wristwatches. As is well known in the art, these include a quartz controlled oscillator supplying high frequency time reference signals to a countdown divider chain, which ultimately provides low frequency time keeping signals of great accuracy. These timekeeping signals actuate a drive circuit providing drive pulses of a selected wave shape to drive a stepping motor which turns hour, minute and sometimes second hands through a gear train. These drive pulses may be repetitive wave shapes of the same polarity for driving stepping motors of the type shown in U.S. Pat. Nos. 3,818,690 issued to Schwarzschild or 4,070,279 Oudet et al issued Mar. 14, 1978. Alternately, the stepping motor may be of the type receiving pulses of alternating polarity as described in U.S. Pat. No. 4,112,671 Kato et al issued Sept. 12, 1978.
It is further known that time correction of such a timekeeping circuit may be effected by supplying sources of different wave shapes or polarities to reverse the direction of the stepping motor so as to drive the hands counterclockwise, and that the movement of the hands can be speeded up and driven at various speeds in both the forward and reverse directions. Examples of the foregoing electronic timesetting circuits are shown in German Pat. No. 2,025,710; U.S. Pat. No. 4,173,863 Motoki et al issued Nov. 13, 1979; U.K. pat. No. 1,557,145 (Daini Seikosha); and U.S. Pat. No. 4,030,283 Sauthier et al issued June 21, 1977.
It is also known to use a single pushbutton switch for controlling various timesetting modes, this being illustrated in the assignee's U.S. Pat. No. 3,953,964-Suppa et al issued May 4, 1976 for a digital electronic watch, and the aforesaid U.S. Patents to Sauthier et al and to Motoki et al. An arrangement using a single pushbutton to achieve alternating forward and backward hand movement for time correction is disclosed in U.S. Pat. No. 4,192,134 issued Mar. 11, 1980 to Yoshida.
One problem associated with setting a quartz analog stepping motor watch is that, if the watch has been previously accurately set in accordance with a time standard signal, and it is desired to change the hour hand reading by exact increments of one hour for daylight saving change or time zone change, without disturbing the watch timekeeping, prior art devices do not adequately supply this defficiency.
The aforesaid U.S. Pat. No. 4,173,863 to Motoki provides for time correction of one hour but the watch must be reset by advancing the hands at a slow rate after this.
Another problem in the prior art is that it is sometimes desired to move the hands slowly in order to position them accurately for a manual restart from a time standard signal. However, if it is necessary to move the hands a great distance, this slow motion is tedious and time consuming. Therefore, it would be desirable to have an accelerated forward speed as well as other forward and reverse speeds effectuated, however, through a single pushbutton control.
Accordingly, one object of the present invention is to provide an improved electronic timesetting device for an electronic analog timepiece which automatically corrects the time in exact one hour increments with a single pushbutton control without affecting timekeeping.
Another object of the invention is to provide, in such a timepiece, an improved electronic timesetting circuit, having both slow and fast setting speeds, both forward and reverse with manual restart.